Modeling the effects of historical and future land use/land cover change dynamics on the hydrological response of Ashi watershed, northeastern China

Abstract: The impact of anthropogenic activities in major river watersheds leading to alterations in the environment has triggered this study within the Ashi watershed of northeast China. Understanding individual land use/land cover (LULC) change contribution to watershed hydrology is vital for water resource planning, utilization of land resources and sustaining hydrological balance. This research investigates the influence of LULC alteration on the hydrology of the watershed from 1990 to 2014 and predicts LULC impacts on the hydrological components under different scenarios in 2030. Combined approach for Landsat images classification; Cellular-Automated (CA-Markov) for prediction and Soil and Water Assessment Tool were used. Partial least square regression (PLSR) model was applied to quantify the contribution of each LULC on hydrology. The results show that urban, water, agriculture, open canopy and other vegetation experienced an increment from 1990 to 2014. The predicted LULC for 2030 based on worst-case scenarios indicates urbanization and agriculture increase, while best-case scenario indicates a controlled expansion trend of urban and agriculture and regeneration of closed canopy. The changes in LULC increase stream flow (11.5%), surface runoff (86.6%), water yield (10.5%) but reduce lateral flow (64.9%), groundwater (27.9%) and ET (1%). Stream flow, water yield, surface runoff, lateral flow and evapotranspiration are expected to further increase under both scenarios, increasing more in the worst-case scenario. Urban, agriculture and close forest contributed in determining hydrological processes and are therefore chief environmental stressors in the Ashi watershed. This recommends regulating urban sprawl and agricultural activities to maintain hydrological balance. Graphic abstract: [Figure not available: see fulltext.]